Method and system for providing electrical pulses to gastric wall of a patient with rechargeable implantable pulse generator for treating or controlling obesity and eating disorders

ABSTRACT

Method and system for providing electrical pulses to the gastric wall of a patient to provide therapy for obesity/eating disorders comprises implantable and external components. The implantable components are a lead and rechargeable implantable pulse generator, comprising rechargeable lithium-ion or lithium-ion polymer battery. The external components are a programmer and an external recharger. In one embodiment, the implanted pulse generator may also comprise stimulus-receiver means, and a pulse generator means with rechargeable battery. The rechargeable implanted pulse generator of this embodiment is also adapted to work in conjunction with an external stimulator. In another embodiment, the implanted pulse generator is adapted to be rechargeable, utilizing inductive coupling with an external recharger. Existing gastric stimulators may also be adapted to be used with rechargeable power sources as disclosed herein. The implanted system may also use a lead with two or more electrodes, for selective stimulation and/or blocking. In another embodiment, the external stimulator and/or programmer may comprise an optional telemetry unit. The addition of the telemetry unit to the external stimulator and/or programmer provides the ability to remotely interrogate and change stimulation programs over a wide area network, as well as other networking capabilities.

This application is a continuation of application Serial No. 11/035,374filed Jan. 13, 2005, entitled “Method and system for providingelectrical pulses for neuromodulation of vagus nerve(s) usingrechargeable implanted pulse generator”, which is a continuation ofapplication Ser. No. 10/841,995 filed May 8, 2004, which is acontinuation of application Ser. No. 10/196,533 filed Jul. 16, 2002,which is a continuation of application Ser. No. 10/142,298 filed on May9, 2002. The prior applications being incorporated herein in entirety byreference, and priority is claimed from these applications.

FIELD OF INVENTION

This invention relates generally to electrical stimulation therapy forgastrointestinal (GI) disorders, more specifically to gastricmyo-electrical pacing therapy for obesity and eating disorders withrechargeable implantable pulse generator.

BACKGROUND

Obesity is a significant health problem in the United States and manyother developed countries. Obesity results from excessive accumulationof fat in the body. It is caused by ingestion of greater amounts of foodthan can be used by the body for energy. The excess food, whether fats,carbohydrates, or proteins, is then stored almost entirely as fat in theadipose tissue, to be used later for energy. Obesity is not simply theresult of gluttony and a lack of willpower. Rather, each individualinherits a set of genes that control appetite and metabolism, and agenetic tendency to gain weight that may be exacerbated by environmentalconditions such as food availability, level of physical activity andindividual psychology and culture. Other causes of obesity includepsychogenic, neurogenic, and other metabolic related factors.

Obesity is defined in terms of body mass index (BMI), which provides anindex of the relationship between weight and height. The BMI iscalculated as weight (in Kilograms) divided by height (in squaremeters), or as weight (in pounds) times 703 divided by height (in squareinches). The primary classification of overweight and obesity relates tothe BMI and the risk of mortality. The prevalence of obesity in adultsin the United States without coexisting morbidity increased from 12% in1991 to 17.9% in 1998.

Treatment of obesity depends on decreasing energy input below energyexpenditure. Treatment has included among other things various drugs,starvation and even stapling or surgical resection of a portion of thestomach. Surgery for obesity has included gastroplasty and gastricbypass procedure. Gastroplasty which is also known as stomach stapling,involves constructing a 15- to 30 mL pouch along the lesser curvature ofthe stomach. A modification of this procedure involves the use of anadjustable band that wraps around the proximal stomach to create a smallpouch. Both gastroplasty and gastric bypass procedures have a number ofcomplications.

This Application discloses a method and system for providing gastricmyo-electric pulses to the stomach wall using an implanted gastric leadand a rechargeable implantable pulse generator (FIGS. 10 and 11). Suchgastric pacing disrupts the normal gastric motility and provides therapyto an obese patient. Advantageously, such disruption of the normalgastric motility is reversible, unlike gastric bypass surgery. Detailsof such system and method are disclosed in this Application.

Background of Gastrointestinal (GI) Physiology and Regulation

Shown in conjunction with FIG. 1, the gastrointestinal (GI) tract is acontinuous muscular digestive tube that winds through the body. Theorgans of the GI tract are the mouth, pharynx (not shown), esophagus 3,stomach 54, small intestine (duodenum 7, jejunum, and ileum), and largeintestine (cecum, ascending colon, transverse colon, and descendingcolon).

The gastrointestinal (GI) tract has a nervous system all its own, whichis the enteric nervous system 21. This is shown in conjunction with FIG.2. It lies entirely in the wall of the gut, beginning in the esophagus 3and extending all the way to the anus. The enteric nervous system hasabout 100 million neurons, almost exactly equal to the number in theentire spinal cord. It especially controls gastrointestinal movementsand secretion. The enteric nervous system is composed mainly of the twoplexuses, 1) the myenteric plexus 22, which is the outer plexus lyingbetween the longitudinal and circular muscle layers, and 2) thesubmucosal plexus 23 that lies in the submucosa. The nervous connectionwithin and between these two plexuses is depicted in FIG. 2. Themyenteric plexus controls mainly the gastrointestinal movements, and thesubmucosal plexus controls mainly gastrointestinal secretion and localblood flow. As also depicted in FIG. 2, the sympathetic andparasympathetic fibers connect with the myenteric 22 and the submocosal23 plexus. Although the enteric nervous system can function on its own,stimulation by the parasympathetic 25 and sympathetic 26 systems canfurther activate or inhibit gastrointestinal functions. The autonomicnerves influence the functions of the gastrointestinal tract bymodulating the activities of neurons of the enteric nervous system 21.

Shown in conjunction with FIGS. 2 and 3, sympathetic innervation of thegastrointestinal tract is mainly via postganglionic adrenergic fiberswhose cell bodies are located in pre-vertebral and parabertabralganglia. The celiac, superior and inferior mesenteric, and hypogastricplexus provide sympathetic innervation to various segments of the GItract. Activation of the sympathetic nerves usually inhibits the motorand secretory activities of the GI system.

Parasympathetic innervation of the GI tract down to the level of thetransverse colon is provided by branches of the vagus nerves (10^(th)cranial nerve). Excitation of parasympathetic nerves usually stimulatesthe motor and secretory activities of the GI tract.

The stomach 54 is richly innervated by extrinsic nerves and by theneurons of the enteric nervous system 21. Axons from the cells of theintramural plexus innervate smooth muscle and secretory cells.

The emptying of gastric contents is regulated by both neural andhormonal mechanisms. The duodenal and jejunal mucosa contain receptorsthat sense acidity, osmotic pressure, certain fats and fat digestionproducts, and peptides and amino acids This is depicted in FIG. 4. Thechyme that leaves the stomach is usually hypertonic and it becomes evenmore hypertonic because of the action of the digestive enzymes in theduodenum. Gastric emptying is slowed by hypertonic solutions in theduodenum, by duodenal pH below 3.5, and by the presence of amino acidsand peptides in the duodenum, The presence of fatty acids ormonoglycerides (products of fat digestion) in the duodenum alsodramatically decreases the rate of gastric emptying.

Parasympathetic innervation to the stomach is supplied by the vagusnerves, while sympathetic innervation to the stomach is provided by theceliac plexus. In general, parasympathetic nerves stimulate gastricsmooth muscle motility and gastric secretions, whereas sympatheticactivity inhibits these function. Numerous sensory afferent fibers leavethe stomach in the vagus nerves; some of these fibers travel withsympathetic nerves. Other sensory neurons are the afferent links betweensensory receptors and the intramural plexuses of the stomach. Some ofthese afferent fibers relay information intragastric pressure, gastricdistention, intragastric pH, or pain.

Shown in conjunction with FIG. 5 is the fundus 15, the body 17, andantrum 19 of the stomach 54. After eating, when a wave of esophagealperistalsis begins, a reflex causes the LES to relax. This relaxation ofthe LES is followed by receptive relaxation of the fundus 15 and body 17of the stomach. The stomach 54 will also relax if it is filled directlywith gas or liquid. The nerve fibers in the vagi are a major efferentpathways for reflex relaxation of the stomach 54.

FIG. 6 depicts the three main muscle layers of the stomach 54, which arethe longitudinal layer 14, the circular layer 16, and the oblique layer18. The complex and coordinated activity of these muscle layers isresponsible for the normally efficient gastric motility. Whereas, thegastric pacing disclosed here from around the antral area of the stomach54, disrupts the normal gastric motility.

Normally, the smooth muscle of the GI tract is excited by almostcontinual slow, intrinsic electrical activity along the membranes of themuscle fibers. This activity has two basic types of electrical waves: 1)slow waves and 2) spikes. This is shown in conjunction with FIG. 7. Mostgastrointestinal contractions occur rhythmically, and this rhythm isdetermined mainly by the frequency of the slow waves of the smoothmuscle membrane potential. Their intensity usually varies between 5 and15 millivolts, and their frequency ranges in different parts of thehuman gastrointestinal tract between 3 and 12 per minute. The rhythm ofcontraction of the body of the stomach is about 3 per minute (and in theduodenum is about 12 per minute).

The electrical activity of the GI tract is shown in conjunction withFIG. 7. For example, the contraction of small intestinal smooth muscleoccurs when the depolarization caused by the slow wave exceeds athreshold for contraction. When depolarization of a slow wave exceedsthe electrical threshold, a burst of action potentials 29 occurs. Theaction potentials elicit a much stronger contraction than occurs in theabsence of action potentials. The contractile force increases withincreasing number of action potentials.

Action potentials in gastrointestinal smooth muscle are more prolonged(10 to 20 msec) than those of skeletal muscle and have little or noovershoot. The rising phase of the action potentials is caused by ionflow through channels that conduct both Ca⁺⁺ and Na⁺ and are relativelyslow to open. Ca⁺⁺ that enters the cell during the action potentialhelps to initiate contraction.

When the membrane potential of gastrointestinal smooth muscle reachesthe electrical threshold, typically near the peak of a slow wave, atrain of action potentials (1 to 10/sec) is fired. The extent ofdepolarization of the cells and the frequency of action potentials areenhanced by some hormones and paracrine agonists and by compoundsliberated from excitatory nerve endings. Inhibitory hormones andneuroefector substances hyperpolarize the smooth muscle cells and maydiminish or abolish action potential spikes.

Slow waves that are not accompanied by action potentials elicit weakcontractions of the smooth muscle cells (FIG. 7). Much strongercontractions are evoked by the action potentials that are intermittentlytriggered near the peaks of the slow waves. The greater the frequency ofaction potentials that occur at the peak of a slow wave, the moreintense is the contraction of the smooth muscle. Because smooth musclecells contract rather slowly (about one tenth as fast as skeletal musclecells), the individual contraction caused by each action potential in atrain do not cause distinct twitches; rather, they sum temporally toproduce a smoothly increasing level of tension (FIG. 7).

Between trains of action potentials the tension developed bygastrointestinal smooth muscle falls, but not to zero. This nonzeroresting, or baseline, tension of smooth muscle is called tone. The toneof gastrointestinal smooth muscle is altered by neuroeffectors,hormones, paracrine substances, and drugs.

Control of the contractile and secretory activities of thegastrointestinal tract involves the central nervous system, the entericnervous system, and hormones and paracrine substances. The autonomicnervous system typically only modulates the patterns of muscular andsecretary activity; these activities are controlled more directly by theenteric nervous system.

In the current invention, as shown in conjunction with FIG. 8, a leadand a rechargeable implantable pulse generator is surgically implantedin the body. By stimulating the stomach wall with the system describedin this disclosure, using a site and frequency which competes with theintrinsic rhythm, the normal gastric motility is interfered with, andgeneral decrease of normal gastric motility occurs. The stomach isempties less efficiently.

Shown in conjunction with FIG. 9, with the stomach not emptying asefficiently, satiety signals which are sent to the brain (via the vagusnerves), make the patients feel less hungry. With the capacity to handleless food through the GI tract, and at the same time the patientsfeeling less hungry, therapy is provided for obesity and weight loss.Advantageously, in the method and system of this invention, this processis controllable and reversible utilizing an implanted lead and aprogrammable rechargeable implantable pulse generator.

This application is also related to co-pending applications entitled“METHOD AND SYSTEM FOR VAGAL BLOCKING WITH OR WITHOUT VAGAL STIMULATIONTO PROVIDE THERAPY FOR OBESITY AND OTHER GASRTOINTESTINAL DISORDERSUSING RECHARGEABLE IMPLANTED PULSE GENERATOR”, and “METHOD AND SYSTEM TOPROVIDE THERAPY FOR OBESITY AND OTHER MEDICAL DISORDERS, BY PROVIDINGELECTRICAL PULSES TO SYMPATHETIC NERVES OR VAGAL NERVE(S) WITHRECHARGEABLE IMPLANTED PULSE GENERATOR”.

PRIOR ART

Prior art is generally directed to adapting cardiac pacemaker technologyto gastric pacing. But, the requirements of gastric pacing aresignificantly different from those of cardiac pacing.

U.S. Pat. No. 6,615,084 (Cigaina) is generally directed to a process ofusing electrostimulation for treating obesity. An implantable pulsegenerator (similar to cardiac pacemaker) appears to be used even thoughdetails are not provided for stimulation technology.

U.S. Pat. No. 5,423,872 (Cigaina) is also generally directed to aprocess for treating obesity and syndromes related to motor disorders ofthe stomach. There is no disclosure or suggestion for an inductivelycoupled system with an implanted stimulus-receiver and an externalstimulator for supplying the electrical pulses, or for recharging animplantable system.

U.S. Pat. No. 5,690,691 (Chen et al.) is generally directed to a gastricpacemaker having phased multi-point stimulation. This disclosure isaimed primarily at having multiple electrodes throughout thegastrointestinal tract and providing phased electrical stimulation toeither enhance or attenuate the peristaltic movement to treat eatingdisorders or diarrhea.

U.S. Pat. No. 6,321,124 B1 (Cigaina) is generally directed to theimplantable lead aspect of a gastrointestinal pacing system.

U.S. Pat. No. 6,104,955 (Bourgeois) and U.S. Pat. No. 5,861,014(Familoni) are generally directed to pulse generator systems featuringsensors for sensing gastric electrical activity, and pacingcapabilities.

U.S. Pat. No. 6,553,263B1 (Meadows et al.) is generally directed to animplantable pulse generator system for spinal cord stimulation, whichincludes a rechargeable battery. In the Meadows '263 patent there is nodisclosure or suggestion for combing a stimulus-receiver module to animplantable pulse generator (IPG) for use with an external stimulator,for providing modulating pulses to sympathetic nerve(s), as in theapplicant's disclosure.

U.S. Pat. No. 6,505,077 B1 (Kast et al.) is directed to electricalconnection for external recharging coil. In the Kast '077 disclosure, amagnetic shield is required between the externalized coil and the pulsegenerator case. In one embodiment of the applicant's disclosure, theexternalized coil is wrapped around the pulse generator case, withoutrequiring a magnetic shield.

U.S. Pat. No. 6,611,715 B1 (Boveja) is generally directed to a systemand method to provide therapy for obesity and compulsive eatingdisorders using an implantable lead-receiver and an external stimulator.

The method and system of the current disclosure is advantageous becauseit provides an ideal power source. The high output requirements ofgastric pacing (which are met by high amplitude pulses and very longpulse duration (compared to cardiac pacing) are ideally met by thesystem and method of the current disclosure. This system is advantageousbecause it eliminates repeated surgeries which are required forsubcutaneously implanted pulse generator changes. Additional advantageof the system and method of the current disclosure is that the externalstimulator can be remotely interrogated and programmed over theinternet. This eliminates the need for patient to visit physician'soffice or clinic every time the device needs to be programmed.

SUMMARY OF THE INVENTION

The method and system of the current invention overcomes manyshortcomings of the prior art by providing a system for providing pulsesto gastric wall with extended power source either in the form ofrechargeable battery, or by utilizing an external stimulator inconjunction with an implanted pulse generator device, to provide therapyfor obesity, eating disorders or for inducing weight loss.

Accordingly, in one aspect of the invention, electrical pulses areprovided to gastric wall utilizing a rechargeable implantable pulsegenerator.

In another aspect of the invention, the electrical pulses to the gastricwall are provided for at least one of obesity, inducing weight loss,eating disorders, obsessive compulsive disorders, and motilitydisorders.

In another aspect of the invention, the pulse amplitude delivered tosympathetic nervous system can range from 0.25 volt to 25 volts.

In another aspect of the invention, the pulse width of electrical pulsesdelivered can range from 5 milli-seconds to 2 seconds.

In another aspect of the invention, the frequency of electrical pulsesdelivered to sympathetic nervous system can range from 1 cycle/second to100 cycles/second.

In another aspect of the invention, a coil used in recharging said pulsegenerator is around the implantable pulse generator case, and in asilicone enclosure.

In another aspect of the invention, the rechargeable implanted pulsegenerator comprises two feedthroughs.

In another aspect of the invention, the rechargeable implanted pulsegenerator comprises only one feedthrough for externalizing the rechargecoil.

In another aspect of the invention, the implantable rechargeable pulsegenerator comprises stimulus-receiver means such that, the implantablerechargeable pulse generator can function in conjunction with anexternal stimulator, to provide the stimulation and/or blocking pulsesto the gastric wall of a patient.

In another aspect of the invention, the rechargeable battery comprisesat least one of lithium-ion, lithium-ion polymer batteries.

In another aspect of the invention, the external programmer or theexternal stimulator comprises networking capabilities for remotecommunications over a wide area network for remote interrogation and/orremote programming.

In yet another aspect of the invention, the implanted lead comprises atleast one electrode(s) which is/are made of a material selected from thegroup consisting of platinum, platinum/iridium alloy, platinum/iridiumalloy coated with titanium nitride, and carbon.

These and other objects are provided by one or more of the embodimentsdescribed below.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustrating the invention, there are shown inaccompanying drawing forms which are presently preferred, it beingunderstood that the invention is not intended to be limited to theprecise arrangement and instrumentalities shown.

FIG. 1 is a diagram showing general anatomy of the gastrointestinal (GI)tract.

FIG. 2 is a diagram showing control of the enteric nervous system by theautonomic nervous system (parasympathetic and sympathetic).

FIG. 3 is a simplified diagram depicting sympathetic and parasympatheticinnervation of the gastrointestinal (GI) tract.

FIG. 4 is a diagram depicting control of gastric emptying by thesympathetic and parasympathetic activity.

FIG. 5 is a diagram showing general anatomy of the human stomach.

FIG. 6 is a diagram showing the longitudinal, circular, and obliquemuscle layers of the stomach.

FIG. 7 is a diagram depicting the electrical activity of the GI tract.

FIG. 8 is a diagram showing the implanted components of the invention.

FIG. 9 is a schematic diagram showing the relationship of meals andsatiety signals.

FIGS. 10 and 11 are diagrams showing the implanted components of theinvention, which are a lead and rechargeable implanted pulse generator.

FIG. 12 is a simplified general block diagram of an implantable pulsegenerator.

FIG. 13A shows energy density of different types of batteries.

FIG. 13B shows discharge curves for different types of batteries.

FIG. 14 shows a block diagram of an implantable device which can be usedas a stimulus-receiver or an implanted pulse generator with rechargeablebattery.

FIG. 15 is a block diagram highlighting battery charging circuit of theimplantable stimulator of FIG. 14.

FIG. 16 is a schematic diagram highlighting stimulus-receiver portion ofimplanted stimulator of one embodiment.

FIG. 17 depicts externalizing recharge and telemetry coil from thetitanium case.

FIG. 18A depicts coil around the titanium case with two feedthroughs fora bipolar configuration.

FIG. 18B depicts coil around the titanium case with one feedthrough fora unipolar configuration.

FIG. 18C depicts two feedthroughs for the external coil which are commonwith the feedthroughs for the lead terminal.

FIG. 18D depicts one feedthrough for the external coil which is commonto the feedthrough for the lead terminal.

FIGS. 19A and 19B depict recharge coil on the titanium case with amagnetic shield in-between.

FIG. 20 shows an implantable rechargable pulse generator in blockdiagram form.

FIG. 21 depicts in block diagram form, the implanted and externalcomponents of an implanted rechargable system.

FIG. 22 depicts the alignment function of rechargable implantable pulsegenerator.

FIG. 23 is a block diagram of the external recharger.

FIG. 24A is a schematic diagram of the implantable lead with twoelectrodes.

FIG. 2B is a schematic diagram of the implantable lead with threeelectrodes.

FIG. 25 is a schematic diagram depicting external stimulator and two-waycommunication through a server.

FIG. 26 is a diagram depicting wireless remote interrogation andprogramming of the external stimulator.

FIG. 27 is a schematic diagram depicting wireless protocol.

FIG. 28 is a simplified block diagram of the networking interface board.

FIGS. 29A and 29B are simplified diagrams showing communication ofmodified PDA/phone with an external stimulator via a cellular tower/basestation.

DESCRIPTION OF THE INVENTION

In the method and system of this invention, a lead 40 comprising atleast one pair of electrodes for providing gastric myo-electricalstimulation is laprscopically implanted in a patient. In one preferredprocedure methodology, a patient undergoing general endotrachealanesthesia is positioned in lithotomy position. A minimum of threetrocars are inserted. A midline supraumbilical port is used to introducethe optical system. Another port is used to introduce the stomachgrasper. One other port (a subcostal port) is used to introduce the leadand subsequently the needle-driver. The back end of the lead is broughtout through this left subcostal port at the completion of the abdominalportion of the operation.

The lead is then introduced into the abdomen, and inserted into a muscletunnel. Using appropriate counter-traction on the stomach, both of theelectrodes are ensured to be buried within the tunnel wall. After theelectrodes have been inserted, a flexible fiberoptic gastroscopy isperformed to ensure that inadvertent perforation of the needle into thelumen of the stomach has not occurred. Once the lead is satisfactorilyimplanted, it is secured in position with non-absorbable suture. Apocket is prepared on the anterior abdominal wall, and the rechargeableimplantable pulse generator is implanted subutaneously. The skin issurgically closed in the usual manner. The electrical stimulation to thegastric wall can begin once the patient is completely healed from thesurgery.

Shown in conjunction with FIGS. 8, 10, and 11, the pulses are typicallyprovided via lead 40 between electrodes 61 and 62, for a bipolarconfiguration. A unipolar configuration can also be used where the pulsegenerator case is used as the ground electrode, i.e. the pulses areprovided between electrode 61 and the case. The stimulation of thegastric muscle can be performed in one of two ways. One method is toactivate one of several stored “pre-determined” programs. A secondmethod is to “custom” program the electrical parameters which can beselectively programmed, for specific therapy to the individual patient.Additionally, if a stored program is used, it can be further adjusted or“fine tuned” by modifying any programmable parameter. The electricalparameters that can be individually modified or programmed, includevariables such as pulse amplitude, pulse width, frequency ofstimulation, stimulation on-time, and stimulation off-time. Table onebelow defines the approximate range of parameters; TABLE 1 Electricalparameter range delivered to the gastric wall PARAMETER RANGE PulseAmplitude 0.5 Volt to 25 Volts Pulse Width 5 msec. to 2 secs Frequency 1cycle/min to 100 cycles/min On-time 1 min. to 24 hours Off-time 1 min.to 24 hours

The parameters in Table 1 are the electrical signals delivered to thegastric wall tissue via the two electrodes 61,62 (distal and proximal)in the gastric wall.

Without limitation and by way of example only, Low, Medium, and Highoutput stimulation states stored in memory. For example;

-   -   1. LO Stim.        -   Amplitude—2.5 Volts        -   Pulse Width—200 msec    -   2. MED Stim.        -   Amplitude—5 Volts        -   Pulse Width—350 msec    -   3. HI Stim.        -   Amplitude—7.5 Volts        -   Pulse Width—500 msec    -   Once a LO, MED, or HI stimulation program is activated, each        individual parameter can be incremented up or down in small        increments, within the range defined in Table 1. When parameter        settings are found that work particularly well for the patient,        they can be stored in the memory of the device. Any number of        these “customized” programs can be stored in the memory of the        pulse generator.

Shown in conjunction with FIG. 12, is an overall schematic of aconventional implantable pulse generator system to deliver electricalpulses for stimulating the gastric wall and providing therapy. Theimplantable pulse generator unit 391 NR is a microprocessor baseddevice, where the entire circuitry is encased in a hermetically sealedtitanium case. As shown in the overall block diagram, the logic &control unit 398 provides the proper timing for the output circuitry 385to generate electrical pulses that are delivered to a pair of electrodesvia a lead 40. Timing is provided by oscillator 393. The pair ofelectrodes to which the stimulation energy is delivered is switchable.Programming of the implantable pulse generator (IPG) is done via anexternal programmer 85. Once programmed via an external programmer 85,the implanted pulse generator 391 NR provides appropriate electricalstimulation pulses to the gastric wall 54 via the stimulating electrodepair 61,62. In this disclosure, the terms stomach, gastric wall, andgastric wall muscle are used interchangeably. Additional pulses may beprovided for blocking, as described later.

Because of the high energy requirements for the pulses required forstimulating the gastric wall muscle 54 (unlike cardiac pacing), there isa real need for power sources that will provide an acceptable servicelife under conditions of continuous delivery of high frequency pulses.FIG. 13A shows a graph of the energy density of several commonly usedbattery technologies. Lithium batteries have by far the highest energydensity of commonly available batteries. Also, a lithium batterymaintains a nearly constant voltage during discharge. This is shown inconjunction with FIG. 13B, which is normalized to the performance of thelithium battery. Lithium-ion batteries also have a long cycle life, andno memory effect. However, Lithium-ion batteries are not as tolerant toovercharging and overdischarging. One of the most recent development inrechargable battery technology is the Lithium-ion polymer battery.Recently the major battery manufacturers (Sony, Panasonic, Sanyo) haveannounced plans for Lithium-ion polymer battery production.

In the method of the current invention, two embodiments of implantablepulse generators may be used. Both embodiments comprise re-chargeablepower sources, such as Lithium-ion polymer battery.

In one embodiment, the implanted device comprises a stimulus-receivermodule and a pulse generator module. Advantageously, this embodimentprovides an ideal power source, since the power source can be anexternal stimulator coupled with an implanted stimulus-receiver, or thepower source can be from the implanted rechargeable battery. Shown inconjunction with FIG. 14 is a simplified overall block diagram of thisembodiment. A coil 48C which is external to the titanium case may beused both as a secondary of a stimulus-receiver, or may also be used asthe forward and back telemetry coil. The coil 48C may be externalized atthe header portion 79C of the implanted device, and may be wrappedaround the titanium case, eliminating the need for a magnetic shield. Inthis case, the coil is encased in the same material as the header 79C.Alternatively, the coil may be positioned on the titanium case, with amagnetic shield.

In this embodiment, as shown in FIG. 14, the IPG circuitry within thetitanium case is used for all stimulation pulses whether the energysource is the internal battery 740 or an external power source. Theexternal device serves as a source of energy, and as a programmer thatsends telemetry to the IPG. An external stimulator and recharger mayalso be combined within the same enclosure. For programming, the energyis sent as high frequency sine waves with superimposed telemetry wavedriving the external coil 46C. The telemetry is passed through couplingcapacitor 727 to the IPG's telemetry circuit 742. For pulse deliveryusing external power source, the stimulus-receiver portion will receivethe energy coupled to the implanted coil 48C and, using the powerconditioning circuit 726, rectify it to produce DC, filter and regulatethe DC, and couple it to the IPG's voltage regulator 738 section so thatthe IPG can run from the externally supplied energy rather than theimplanted battery 740.

The system of this embodiment provides a power sense circuit 728 thatsenses the presence of external power communicated with the powercontrol 730, when adequate and stable power is available from anexternal source. The power control circuit controls a switch 736 thatselects either implanted battery power 740 or conditioned external powerfrom 726. The logic and control section 732 and memory 744 includes theIPG's microcontroller, pre-programmed instructions, and storedchangeable parameters. Using input for the telemetry circuit 742 andpower control 730, this section controls the output circuit 734 thatgenerates the output pulses.

Shown in conjunction with FIG. 15, this embodiment of the invention ispracticed with a rechargeable battery. This circuit is energized whenexternal power is available. It senses the charge state of the batteryand provides appropriate charge current to safely recharge the batterywithout overcharging. Recharging circuitry is described later.

The stimulus-receiver portion of the circuitry is shown in conjunctionwith FIG. 16. Capacitor C1 (729) makes the combination of C1 and L1sensitive to the resonant frequency and less sensitive to otherfrequencies, and energy from an external (primary) coil 46C isinductively transferred to the implanted unit via the secondary coil48C. The AC signal is rectified to DC via diode 731, and filtered viacapacitor 733. A regulator 735 sets the output voltage and limits it toa value just above the maximum IPG cell voltage. The output capacitor C4(737), typically a tantalum capacitor with a value of 100 micro-Faradsor greater, stores charge so that the circuit can supply the IPG withhigh values of current for a short time duration with minimal voltagechange during a pulse while the current draw from the external sourceremains relatively constant. Also shown in conjunction with FIG. 16, acapacitor C3 (727) couples signals for forward and back telemetry.

In another embodiment, existing implantable pulse generators can bemodified to incorporate rechargeable batteries. As shown in conjunctionwith FIG. 17, in both embodiments, the coil is externalized from thetitanium case 57. The RF pulses transmitted via coil 46 and received viasubcutaneous coil 48A are rectified via a diode bridge. These DC pulsesare processed and the resulting current applied to recharge the battery694/740 in the implanted pulse generator. In one embodiment the coil 48Cmay be externalized at the header portion 79 of the implanted device,and may be wrapped around the titanium can, as shown in FIGS. 18A and18B. Shown in FIG. 18A is a bipolar configuration which requires twofeedthroughs 76,77. Advantageously, as shown in FIG. 18B unipolarconfiguration may also be used which requires only one feedthrough 75.The other end is electronically connected to the case. In both cases,the coil is encased in the same material as the header 79.Advantageously, as shown in conjunction with FIGS. 18C and 18D, thefeedthrough for the coil can be combined with the feedthrough for thelead terminal. This can be applied both for bipolar and unipolarconfigurations.

In one embodiment, the coil may also be positioned on the titanium caseas shown in conjunction with FIGS. 19A and 19B. FIG. 19A shows a diagramof the finished implantable stimulator 391R of one embodiment. FIG. 19Bshows the pulse generator with some of the components used in assemblyin an exploded view. These components include a coil cover 13, thesecondary coil 48 and associated components, a magnetic shield 9, and acoil assembly carrier 11. The coil assembly carrier 11 has at least onepositioning detail 80 located between the coil assembly and the feedthrough for positioning the electrical connection. The positioningdetail 80 secures the electrical connection in this embodiment.

A schematic diagram of the implanted pulse generator (IPG 391R) withre-chargeable battery 694 of the preferred embodiment of this invention,is shown in conjunction with FIG. 20. The IPG 391R includes logic andcontrol circuitry 673 connected to memory circuitry 691. The operatingprogram and stimulation parameters are typically stored within thememory 691 via forward telemetry. Stimulation pulses are provided to thegastric muscle wall 54 via output circuitry 677 controlled by themicrocontroller.

The operating power for the IPG 391R is derived from a rechargeablepower source 694. The rechargeable power source 694 comprises arechargeable lithium-ion or lithium-ion polymer battery. Rechargingoccurs inductively from an external charger to an implanted coil 48Bunderneath the skin 60. The rechargeable battery 694 may be rechargedrepeatedly as needed. Additionally, the IPG 391R is able to monitor andtelemeter the status of its rechargable battery 691 each time acommunication link is established with the external programmer 85.

Much of the circuitry included within the IPG 391R may be realized on asingle application specific integrated circuit (ASIC). This allows theoverall size of the IPG 391R to be quite small, and readily housedwithin a suitable hermetically-sealed case. The IPG case is preferablymade from titanium and is shaped in a rounded case.

Shown in conjunction with FIG. 21 are the recharging elements of theinvention. The re-charging system uses a portable external charger tocouple energy into the power source of the IPG 391R. The DC-to-ACconversion circuitry 696 of the re-charger receives energy from abattery 672 in the re-charger. A charger base station 680 andconventional AC power line may also be used. The AC signals amplifiedvia power amplifier 674 are inductively coupled between an external coil46B and an implanted coil 48B located subcutaneously with the implantedpulse generator (IPG) 391R. The AC signal received via implanted coil48B is rectified 686 to a DC signal which is used for recharging therechargeable battery 694 of the IPG, through a charge controller IC 682.Additional circuitry within the IPG 391R includes, battery protection IC688 which controls a FET switch 690 to make sure that the rechargeablebattery 694 is charged at the proper rate, and is not overcharged. Thebattery protection IC 688 can be an off-the-shelf IC available fromMotorola (part no. MC 33349N-3R1). This IC monitors the voltage andcurrent of the implanted rechargeable battery 694 to ensure safeoperation. If the battery voltage rises above a safe maximum voltage,the battery protection IC 688 opens charge enabling FET switches 690,and prevents further charging. A fuse 692 acts as an additionalsafeguard, and disconnects the battery 694 if the battery chargingcurrent exceeds a safe level. As also shown in FIG. 21, chargecompletion detection is achieved by a back-telemetry transmitter 684,which modulates the secondary load by changing the full-wave rectifierinto a half-wave rectifier/voltage clamp. This modulation is in turn,sensed by the charger as a change in the coil voltage due to the changein the reflected impedance. When detected through a back telemetryreceiver 676, either an audible alarm is generated or a LED is turnedon.

A simplified block diagram of charge completion and misalignmentdetection circuitry is shown in conjunction with FIG. 22. As shown, aswitch regulator 686 operates as either a full-wave rectifier circuit ora half-wave rectifier circuit as controlled by a control signal (CS)generated by charging and protection circuitry 698. The energy inducedin implanted coil 48B (from external coil 46B) passes through the switchrectifier 686 and charging and protection circuitry 698 to the implantedrechargeable battery 694. As the implanted battery 694 continues to becharged, the charging and protection circuitry 698 continuously monitorsthe charge current and battery voltage. When the charge current andbattery voltage reach a predetermined level, the charging and protectioncircuitry 698 triggers a control signal. This control signal causes theswitch rectifier 686 to switch to half-wave rectifier operation. Whenthis change happens, the voltage sensed by voltage detector 702 causesthe alignment indicator 706 to be activated. This indicator 706 may bean audible sound or a flashing LED type of indicator.

The indicator 706 may similarly be used as a misalignment indicator. Innormal operation, when coils 46B (external) and 48B (implanted) areproperly aligned, the voltage V_(s) sensed by voltage detector 704 is ata minimum level because maximum energy transfer is taking place. If andwhen the coils 46B and 48B become misaligned, then less than a maximumenergy transfer occurs, and the voltage V_(s) sensed by detectioncircuit 704 increases significantly. If the voltage V_(s) reaches apredetermined level, alignment indicator 706 is activated via an audiblespeaker and/or LEDs for visual feedback. After adjustment, when anoptimum energy transfer condition is established, causing V_(s) todecrease below the predetermined threshold level, the alignmentindicator 706 is turned off.

The elements of the external recharger are shown as a block diagram inconjunction with FIG. 23. In this disclosure, the words charger andrecharger are used interchangeably. The charger base station 680receives its energy from a standard power outlet 714, which is thenconverted to 5 volts DC by a AC-to-DC transformer 712. When there-charger is placed in a charger base station 680, the re-chargeablebattery 672 of the re-charger is fully recharged in a few hours and isable to recharge the battery 694 of the IPG 391R. If the battery 672 ofthe external re-charger falls below a prescribed limit of 2.5 volt DC,the battery 672 is trickle charged until the voltage is above theprescribed limit, and then at that point resumes a normal chargingprocess.

As also shown in FIG. 23, a battery protection circuit 718 monitors thevoltage condition, and disconnects the battery 672 through one of theFET switches 716, 720 if a fault occurs until a normal conditionreturns. A fuse 724 will disconnect the battery 672 should the chargingor discharging current exceed a prescribed amount.

It will be clear to one skilled in the art, that existing systems suchas disclosed in U.S. Pat. Nos. 6,615,084 and 5,423,872 both assigned toCigaina can be adapted with technology disclosed in this patentapplication, and both patents are incorporated herein by reference.

Referring now to FIG. 24A, the implanted lead component of the system issimilar to cardiac pacemaker leads, except for distal portion (orelectrode end) of the lead. This figure shows a pair of electrodes 61,62that are used for providing electrical pulses for stimulation. The leadterminal preferably is linear bipolar, even though it can be bifurcated,and plug(s) into the cavity of the pulse generator means. FIG. 24B showsan embodiment of a lead which is tripolar, where one electrode can beused for blocking pulses, and the other electrode pair can be used forstimulation pulses. Blocking is described more fully in a co-pendingapplication.

The lead body 59 insulation may be constructed of medical gradesilicone, silicone reinforced with polytetrafluoro-ethylene (PTFE), orpolyurethane. With reference to electrode materials, the stimulatingelectrodes may be made of pure platinum, platinum/Iridium alloy orplatinum/iridium coated with titanium nitride. The conductor connectingthe terminal to the electrodes 61,62 is made of an alloy ofnickel-cobalt. The implanted lead design variables are also summarizedin table two below. TABLE 2 Lead design variables Proximal Distal EndEnd Conductor (connecting Lead body- proximal Lead Insulation and distalElectrode- Electrode- Terminal Materials Lead-Coating ends) MaterialType Linear Polyurethane Antimicrobial Alloy of Pure Standard Ballbipolar coating Nickel- Platinum and Ring Cobalt electrodes BifurcatedSilicone Anti- Platinum- Steroid Inflammatory Iridium eluting coating(Pt/Ir) Alloy Silicone with Lubricious Pt/Ir coated Polytetrafluoro-coating with Titanium ethylene Nitride (PTFE) Carbon

Once the lead is fabricated, coating such as anti-microbial,anti-inflammatory, or lubricious coating may be applied to the body ofthe lead.

Telemetry Module

Shown in conjunction with FIG. 25, in one embodiment of the inventionthe external pulse generator 42 and/or programmer 85 may comprisetwo-way wireless communication capabilities with a remote server, usinga communication protocol such as the wireless application protocol(WAP). The purpose of the telemetry module is to enable the physician toremotely, via the wireless medium change the programs, activate, ordisengage programs. Additionally, schedules of therapy programs, can beremotely transmitted and verified. Advantageously, the physician is thusable to remotely control the stimulation therapy.

FIG. 26 is a simplified schematic showing the communication aspectsbetween the stimulator 42 and/or programmer 85 and the remote hand-heldcomputer. Similar methodology would apply if the telemetry module is inthe programmer 85. A desktop or laptop computer can be a server 130which is situated remotely, perhaps at a health-care provider's facilityor a hospital. The data can be viewed at this facility or reviewedremotely by medical personnel on a wireless internet supported hand-helddevice 140, which could be a personal data assistant (PDA), for example,a “palm-pilot” from PALM corp. (Santa Clara, Calif.), a “Visor” fromHandspring Corp. (Mountain view, CA) or on a personal computer (PC)available from numerous vendors or a cell phone or a handheld devicebeing a combination thereof. The physician or appropriate medicalpersonnel, is able to interrogate the external stimulator 42 device andknow what the device is currently programmed to, as well as, get agraphical display of the pulse train. The wireless communication withthe remote server 130 and hand-held device (wireless internet supported)140 can be achieved in all geographical locations within and outside theUnited States (US) that provides cell phone voice and data communicationservice. The pulse generation parameter data can also be viewed on thehandheld devices 140.

The telecommunications component of this invention uses WirelessApplication Protocol (WAP). WAP is a set of communication protocolsstandardizing Internet access for wireless devices. Previously,manufacturers used different technologies to get Internet on hand-helddevices. With WAP, devices and services inter-operate. WAP promotesconvergence of wireless data and the Internet. The WAP Layers areWireless Application Envirnment (WAEW), Wireless Session Layer (WSL),Wireless Transport Layer Security (WTLS) and Wireless Transport Layer(WTP).

The WAP programming model, which is heavily based on the existingInternet programming model, is shown schematically in FIG. 27.Introducing a gateway function provides a mechanism for optimizing andextending this model to match the characteristics of the wirelessenvironment. Over-the-air traffic is minimized by binaryencoding/decoding of Web pages and readapting the Internet Protocolstack to accommodate the unique characteristics of a wireless mediumsuch as call drops. Such features are facilitated with WAP.

The key components of the WAP technology, as shown in FIG. 27,includes 1) Wireless Mark-up Language (WML) 452 which incorporates theconcept of cards and decks, where a card is a single unit of interactionwith the user. A service constitutes a number of cards collected in adeck. A card can be displayed on a small screen. WML supported Web pagesreside on traditional Web servers. 2) WML Script which is a scriptinglanguage, enables application modules or applets to be dynamicallytransmitted to the client device and allows the user interaction withthese applets. 3) Microbrowser, which is a lightweight applicationresident on the wireless terminal that controls the user interface andinterprets the WML/WML Script content. 4) A lightweight protocol stack454 which minimizes bandwidth requirements, guaranteeing that a broadrange of wireless networks can run WAP applications. The protocol stackof WAP can comprise a set of protocols for the transport (WTP), session(WSP), and security (WTLS) layers. WSP is binary encoded and able tosupport header caching, thereby economizing on bandwidth requirements.WSP also compensates for high latency by allowing requests and responsesto be handles asynchronously, sending before receiving the response toan earlier request. For lost data segments, perhaps due to fading orlack of coverage, WTP only retransmits lost segments using selectiveretransmission, thereby compensating for a less stable connection inwireless. The above mentioned features are industry standards adoptedfor wireless applications, and well known to those skilled in the art.

The presently preferred embodiment utilizes WAP, because WAP has thefollowing advantages, 1) WAP protocol uses less than one-half the numberof packets that the standard HTTP or TCP/IP Internet stack uses todeliver the same content. 2) Addressing the limited resources of theterminal, the browser, and the lightweight protocol stack are designedto make small claims on CPU and ROM. 3) Binary encoding of WML and SMLScript helps keep the RAM as small as possible. And, 4) Keeping thebearer utilization low takes account of the limited battery power of theterminal.

In this embodiment two modes of communication are possible. In thefirst, the server initiates an upload of the actual parameters beingapplied to the patient, receives these from the stimulator, and storesthese in its memory, accessible to the authorized user as a dedicatedcontent driven web page. The web page is managed with adequate securityand password protection. The physician or authorized user can makealterations to the actual parameters, as available on the server, andthen initiate a communication session with the stimulator device todownload these parameters.

The physician is also able to set up long-term schedules of stimulationtherapy for their patient population, through wireless communicationwith the server. The server in turn communicates these programs to theneurostimulator. Each schedule is securely maintained on the server, andis editable by the physician and can get uploaded to the patient'sstimulator device at a scheduled time. Thus, therapy can be customizedfor each individual patient. Each device issued to a patient has aunique identification key in order to guarantee secure communicationbetween the wireless server 130 and stimulator device 42 (or programmer85).

Shown in conjunction with FIG. 28, in one embodiment, the externalstimulator 42 and/or the programmer 85 may also be networked to acentral collaboration computer 286 as well as other devices such as aremote computer 294, PDA 140, phone 141, physician computer 143. Theinterface unit 292 in this embodiment communicates with the centralcollaborative network 290 via land-lines such as cable modem orwirelessly via the internet. A central computer 286 which has sufficientcomputing power and storage capability to collect and process largeamounts of data, contains information regarding device history andserial number, and is in communication with the network 290.Communication over collaboration network 290 may be effected by way of aTCP/IP connection, particularly one using the internet, as well as aPSTN, DSL, cable modem, LAN, WAN or a direct dial-up connection.

The standard components of interface unit shown in block 292 areprocessor 305, storage 310, memory 308, transmitter/receiver 306, and acommunication device such as network interface card or modem 312. In thepreferred embodiment these components are embedded in the externalstimulator 42 and can also be embedded in the programmer 85. These canbe connected to the network 290 through appropriate security measures(Firewall) 293.

Another type of remote unit that may be accessed via centralcollaborative network 290 is remote computer 294. This remote computer294 may be used by an appropriate attending physician to instruct orinteract with interface unit 292, for example, instructing interfaceunit 292 to send instruction downloaded from central computer 286 toremote implanted unit.

Shown in conjunction with FIGS. 29A and 29B the physician's remotecommunication's module is a Modified PDA/Phone 140 in this embodiment.The Modified PDA/Phone 140 is a microprocessor based device as shown ina simplified block diagram in FIGS. 65A and 65B. The PDA/Phone 140 isconfigured to accept PCM/CIA cards specially configured to fulfill therole of communication module 292 of the present invention. The ModifiedPDA/Phone 140 may operate under any of the useful software includingMicrosoft Window's based, Linux, Palm OS, Java OS, SYMBIAN, or the like.

The telemetry module 362 comprises an RF telemetry antenna 142 coupledto a telemetry transceiver and antenna driver circuit board whichincludes a telemetry transmitter and telemetry receiver. The telemetrytransmitter and receiver are coupled to control circuitry and registers,operated under the control of microprocessor 364. Similarly, withinstimulator a telemetry antenna 142 is coupled to a telemetry transceivercomprising RF telemetry transmitter and receiver circuit. This circuitis coupled to control circuitry and registers operated under the controlof microcomputer circuit.

With reference to the telecommunications aspects of the invention, thecommunication and data exchange between Modified PDA/Phone 140 andexternal stimulator 42 operates on commercially available frequencybands. The 2.4-to-2.4853 GHz bands or 5.15 and 5.825 GHz, are the twounlicensed areas of the spectrum, and set aside for industrial,scientific, and medical (ISM) uses. Most of the technology todayincluding this invention, use either the 2.4 or 5 GHz radio bands andspread-spectrum technology.

The telecommunications technology, especially the wireless internettechnology, which this invention utilizes in one embodiment, isconstantly improving and evolving at a rapid pace, due to advances in RFand chip technology as well as software development. Therefore, one ofthe intents of this invention is to utilize “state of the art”technology available for data communication between Modified PDA/Phone140 and external stimulator 42. The intent of this invention is to use3G technology for wireless communication and data exchange, even thoughin some cases 2.5G is being used currently.

For the system of the current invention, the use of any of the “3G”technologies for communication for the Modified PDA/Phone 140, isconsidered within the scope of the invention. Further, it will beevident to one of ordinary skill in the art that as future 4G systems,which will include new technologies such as improved modulation andsmart antennas, can be easily incorporated into the system and method ofcurrent invention, and are also considered within the scope of theinvention.

1. A method of providing electrical pulses with rechargeable implantablepulse generator at one or more sites to the gastric wall of a patientfor treating, controlling or alleviating the symptoms for at least oneof obesity, inducing weight loss, eating disorders, obsessive compulsivedisorders, and motility disorders, comprising the steps of: providingsaid rechargeable implantable pulse generator, comprising amicrocontroller, pulse generation circuitry, rechargeable battery,battery recharging circuitry, and a coil; providing a lead with at leasttwo electrodes adapted to be in contact with said gastric wall of apatient, and in electrical contact with said rechargeable implantablepulse generator; providing an external power source to charge saidrechargeable implantable pulse generator; and providing an externalprogrammer to program said rechargeable implantable pulse generator. 2.A method of claim 1, wherein said coil used in recharging said pulsegenerator is around said implantable rechargeable pulse generator case,in a silicone enclosure.
 3. A method of claim 1, wherein saidimplantable rechargeable pulse generator does not require magneticshielding between said coil and said titanium case.
 4. A method of claim1, wherein said rechargeable implanted pulse generator further comprisesone or two feed-through(s) for unipolar or bipolar configurationsrespectively.
 5. A method of claim 1, wherein said implantablerechargeable pulse generator further comprises stimulus-receiver meanssuch that, said implantable rechargeable pulse generator can function inconjunction with an external stimulator, to provide said electricalpulses to said gastric wall of a patient.
 6. A method of claim 1,wherein said rechargeable battery comprises at least one of lithium-ion,lithium-ion polymer batteries.
 7. The method of claim 1, wherein theamplitude of said electrical pulses delivered to the gastric wall canrange from 0.5 volt to 25 volts.
 8. The method of claim 1, wherein thepulse width of said electrical pulses delivered to the gastric wall canrange from 5 milliseconds to 2 seconds.
 9. The method of claim 1,wherein the frequency of said electrical pulses delivered to the gastricwall can range from 1 cycle/min. to 100 cycles/min.
 10. The method ofclaim 1, wherein said rechargeable implanted pulse generator is adaptedto be remotely interrogated and/or programmed over a wide area networkby an external interface means.
 11. A method of providing pulsedelectrical therapy to gastric muscle wall for treating or controlling atleast one of eating disorders, obesity, or inducing weight loss in apatient, comprising the steps of: providing an implantable rechargeablepulse generator, wherein said rechargeable implantable pulse generatorcomprises a stimulus-receiver means, and an implantable pulse generatormeans, comprising a microcontroller, pulse generation circuitry,rechargeable battery, and battery recharging circuitry; providing a leadwith at least two electrodes adapted to be in contact with said vagusnerve(s) or its branches or part thereof, and in electrical contact withsaid implantable rechargeable pulse generator; providing an externalpower source to charge rechargeable implantable pulse generator; andproviding an external programmer to program the said rechargeableimplantable pulse generator, whereby said electric pulses provide saidtherapy.
 12. A method of claim 11, wherein said rechargeable implantablepulse generator can be recharged using an external re-charger or anexternal stimulator.
 13. A method of claim 11, wherein said rechargeablebattery comprises at least one of lithium-ion, lithium-ion polymerbatteries.
 14. A system for providing electrical pulses at one or moresites to the gastric wall of a patient for treating, controlling oralleviating the symptoms for at least one of obesity, inducing weightloss, eating disorders, obsessive compulsive disorders, and motilitydisorders, comprising: a rechargeable implantable pulse generator,comprising, a microprocessor, pulse generation circuitry, rechargeablebattery, battery recharging circuitry, and a coil; a lead with at leasttwo electrodes adapted to be in contact with the gastric wall in apatient and in electrical contact with said implantable rechargeablepulse generator; an external power source to charge said rechargeableimplantable pulse generator; and an external programmer to program saidrechargeable implantable pulse generator.
 15. A system of claim 14,wherein the amplitude of said electrical pulses delivered to the gastricwall can range from 0.5 volt to 25 volts.
 16. A system of claim 14,wherein the pulse width of said electrical pulses delivered to thegastric wall can range from 5 milliseconds to 2 seconds.
 17. A system ofclaim 14, wherein the frequency of said electrical pulses delivered tothe gastric wall can range from 1 cycle/min. to 100 cycles/min.
 18. Asystem of claim 14, wherein said rechargeable battery comprises at leastone of lithium-ion, lithium-ion polymer batteries.
 19. A system of claim14, wherein said coil is used for bi-directional telemetry, or receivingelectrical pulses from said external stimulator.
 20. A system of claim14, wherein said coil used in recharging said pulse generator is aroundsaid rechargeable implantable pulse generator case in a siliconeenclosure.
 21. A system of claim 14, wherein said rechargeable implantedpulse generator further comprises one or two feed-through(s) forunipolar or bipolar configurations respectively.
 22. A system of claim14, wherein said implantable rechargeable pulse generator furthercomprises stimulus-receiver means such that said implantablerechargeable pulse generator can also function in conjunction with anexternal stimulator, to provide said electrical pulses to said gastricwall of a patient.
 23. A system of claim 14, wherein said at least twoelectrodes are of a material selected from the group consisting ofplatinum, platinum/iridium alloy, platinum/iridium alloy coated withtitanium nitride, and carbon.
 24. A system of claim 14, wherein saidrechargeable implanted pulse generator is adapted to be remotelyinterrogated and/or programmed over a wide area network by an externalinterface means.